KR101100063B1 - Sealer and method for its application - Google Patents

Abstract

A sealing material comprising a powder obtained by pulverizing a rubber-based sealing material having a viscosity of 20 to 200 Pa · s / 100 ° C. at a temperature below its embrittlement temperature, and a method of applying the sealing material including spray coating on the surface to be coated.

Rubber sealant, embrittlement temperature, spray application, pneumatic tire.

Description

Sealant and its application method {Sealer and method for its application}

The present invention relates to a sealing material and a method for applying the same, which is easy to apply, hardly to cause uneven coating, and a clean surface of the coated surface.

Conventionally, for example, when a pneumatic tire is flat, a rubber-based sealing material is applied to the inner surface of the pneumatic tire in advance so that its puncture hole naturally closes (self-sealing tire).

The rubber sealant is made by blending various compounding agents with rubber (so-called raw rubber), and various ones have been proposed. For example, JP-A-53-55802 discloses a puncture-proof rubber-based sealant containing polyisobutylene, an inorganic filler and a peroxide.

However, since the rubber sealant has a high viscosity (for example, in the case of a sealant containing butyl rubber, its viscosity is about 80 Pa · s / 100 ° C.), it is sprayed onto the surface to be coated (for example, the inner surface of the pneumatic tire). Since application | coating cannot be performed and it must be applied manually, there existed a problem that poor workability | liquidity was easy to generate | occur | produce, and a clean and uniform coating surface without an unevenness | corrugation was not able to be secured.

In addition, when a large amount of organic solvent is added to lower the viscosity of the rubber-based sealing material in order to enable spray coating, there is a problem that the organic solvent adversely affects the working environment.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sealing material and a method of applying the same, which are easy to apply, have good workability, are less likely to cause uneven coating, and have a clean coated surface.

The sealing material of this invention is characterized by including the powder which grind | pulverized the rubber type sealing material whose viscosity is 20-200 Pa * s / 100 degreeC at the temperature below its embrittlement temperature.

In addition, in the coating method of the sealing material of the present invention, the rubber-based sealing material having a viscosity of 20 to 200 Pa · s / 100 ° C. is pulverized at a temperature below its embrittlement temperature to form a powder, and then the powder is sprayed onto the surface to be coated. It is characterized by.

In this way, the sealing material of the present invention is a powder having a high viscosity rubber-based sealing material having a viscosity of 20 to 200 Pa · s / 100 ° C., and according to the present invention, the powder is spray-coated to the surface to be coated, as in the prior art. Since it does not need to apply by hand, application | coating is easy and workability | operativity is favorable, application | coating stain is hard to generate | occur | produce, and it becomes possible to finish a coating surface neatly.

The rubber sealant used in the present invention may be generally known. For example, it contains the polyisobutylene, inorganic filler, and peroxide of Unexamined-Japanese-Patent No. 53-55802. However, the rubber sealing material used by this invention is a thing with a viscosity of 20-200 Pa * s / 100 degreeC.

The rubber in the rubber-based sealing material may be any rubber, and for example, natural rubber, polyisobutylene (isobutyrene rubber), butyl rubber (isobutylene-isoprene rubber), isoprene rubber, styrene-butadiene rubber, Rubber such as butadiene rubber, nitrile rubber, and ethylene-propylene-diene terpolymer copolymer rubber may be used alone or in combination. Among these rubbers, butyl rubber is preferably used because of its excellent air permeability. In addition, you may mix | blend other polymers other than rubber | gum, such as polybutene, with the rubber sealing material containing butyl rubber as needed.

As an inorganic filler mix | blended with rubber, carbon black, a silica, a zinc oxide, etc. are mentioned, for example. Moreover, you may mix | blend other compounding agents, such as stearic acid and paraffin oil, as needed.

In the case of using a peroxide, generally known peroxides may be used (peroxides may not necessarily be used). Examples of such peroxides include acyl peroxides such as benzoyl peroxide and p-chlorobenzoyl peroxide, ketone peroxides such as methyl ethyl ketone peroxide, t-butyl peroxy acetate and t-butyl peroxy. Alkyl such as peroxy esters such as benzoate and t-butyl peroxy phthalate, dicumyl peroxide, di-t-butyl peroxy benzoate and 1,3-bis (t-butylperoxyisopropyl) benzene Peroxides, hydroperoxides, such as t-butyl hydroperoxide, etc. are mentioned.

The rubber sealing material used by this invention is that whose viscosity is 20-200 Pa.s / 100 degreeC, Preferably it is 80-140 Pa.s / 100 degreeC. If the viscosity is less than 20 Pa · s / 100 ° C., the viscosity is so low that after the rubber-based sealant is applied to the surface to be coated, the flow of the rubber-based sealant is excessively generated, resulting in an uneven coating surface, while the viscosity is 200 Pa · s / 100 ° C. This is because when the viscosity is too high, the flow rate of the rubber-based sealant does not occur after the rubber-based sealant is applied to the surface to be coated, so that the coating thickness is not uniform and the coated surface is not smoothed. In order to make the viscosity of a rubber sealing material into 20-200 Pa * s / 100 degreeC, what is necessary is just to adjust suitably the compounding quantity of the compounding component of a rubber sealing material.

In the present invention, the rubber-based sealing material having a viscosity of 20 to 200 Pa · s / 100 ° C. is pulverized at a temperature below its embrittlement temperature to obtain a powder. The rubber sealant is a high viscosity viscous product having a viscosity of 20 to 200 Pa · s / 100 ° C., but is embrittled (solidified) at a temperature below its embrittlement temperature. Therefore, in this invention, a rubber sealing material is grind | pulverized at the temperature below its embrittlement temperature, and it is set as powder. Grinding may be performed by a conventional method. For example, it is good to grind a rubber sealing material using a low temperature grinder in a liquid nitrogen atmosphere. In addition, although the temperature below embrittlement temperature is not specified, it is preferable that it is a temperature 10 degreeC or more lower than embrittlement temperature. The size of the powder may be any size convenient for spraying, for example, if its particle diameter is 3 to 8 μm.

In the present invention, the powder obtained as described above is spray-coated to the surface to be coated, for example, the inner surface of the pneumatic tire. The coating may be performed by a conventional method, for example, using an air spray gun or an airless spray gun. At the time of such application | coating, spraying is performed in the state which put powder at the temperature below the said embrittlement temperature. If the temperature rises above the embrittlement temperature, the shape of the powder cannot be maintained. On the other hand, although the temperature of a to-be-coated surface may be normal temperature (about 20 degreeC), it is good to set it as 20 degreeC or more and 60 degrees C or less, Preferably it is 30 degreeC or more and 50 degrees C or less. This is because when the temperature of the surface to be coated is increased, the spray-coated powder is quickly warmed up, and the original viscosity can be recovered soon and attached to the surface to be coated.

Examples 1-6, Comparative Examples 1-2, Conventional Example

The inner surface coating of the pneumatic tire of the tire size 195 / 65R15 was performed using the rubber type sealing material of the compounding content (weight part) of Table 1, and was used.

In application | coating, first, a rubber sealing material is grind | pulverized at the grinding | pulverization temperature below embrittlement temperature using a low temperature grinder, it is made into the powder of about 3-8 micrometers of particle diameters, and the air spray gun is used, maintaining the said powder at the grinding | pulverization temperature. To the inner surface of the pneumatic tire (Examples 1 to 6 and Comparative Examples 1 to 2). In addition, the rubber-based sealing material was mixed with the compounding components shown in Table 1, and then subjected to pretreatment by heating at 120 ° C for 1 hour to partially vulcanize them. As the conditions for spraying, using a gravity-falling jet device as an air spray gun, the powder is dropped in the vicinity of the jet port, and the flow rate of the powder jetted at the jet port is 20 to 100 m / s, and the gravity drop jet device is An orifice diameter was made into the diameter which the said flow velocity is obtained and the said powder can fully eject.

The inner surface temperature (coating surface temperature) of the pneumatic tire was as described in Table 1.

As a conventional example, since the rubber sealing material has high viscosity at normal temperature, the inner surface coating of the pneumatic tire of tire size 195 / 65R15 was performed by affixing the rolled sheet form to the tire inner surface manually.

Table 1 shows the workability at the time of coating and the uniformity of the coating thickness of the rubber-based sealing material. In addition, in Table 1, although "0" is good and "△" does not reach to "0", it is good and "x" shows bad.

In Table 1, in the comparative example 1, since the viscosity of a rubber-based sealing material is low, the flow of a sealing material will generate | occur | produce excessively after apply | coating to a tire inner surface, and the thickness of an application surface will become nonuniform. In Example 1, since the coating surface temperature is low, the applied sealing material does not immediately change into an effective viscosity, and the thickness of the coating surface becomes slightly nonuniform. In Example 6, since application | coating surface temperature is too high, the viscosity of the sealing material after application | coating will become low and the flatness of an application surface will be slightly impaired. In addition, when the coated surface temperature is too high, there is a risk of adversely affecting the tire itself. In Comparative Example 2, since the viscosity of the rubber-based sealing material is high, the flow of the sealing material does not occur after the coating, and the thickness partially changes in the coating area, and such a change is not eliminated. Becomes uneven.

Therefore, as can be seen from Table 1, in the case of the present invention (Examples 1 to 6), coating unevenness is less likely to occur as compared with Comparative Examples 1 to 2, and it is understood that workability is better than that of the conventional example. have.

As described above, in the present invention, the rubber-based sealing material having a high viscosity is pulverized at a temperature below its embrittlement temperature to form a powder, and then the powder is spray-coated onto the surface to be coated, so that application is easy and workability is good. It is hard to generate | occur | produce coating unevenness, can finish a coating surface cleanly, and it becomes possible to apply | coat with free thickness.

INDUSTRIAL APPLICABILITY The present invention can be advantageously applied to sealing not only pneumatic tires but also roofs of houses and bathrooms, sealing of lamps and a body for automobiles, or sealing of laminated glass.

Claims (14)

A sealing material for spray coating comprising a powder having a particle diameter of 3 to 8 µm obtained by pulverizing a rubber-based sealing material having a viscosity of 20 to 200 Pa · s / 100 ° C. at a temperature below its embrittlement temperature. The sealant for spray application according to claim 1, wherein the rubber sealant comprises butyl rubber. The sealant for spray application according to claim 2, further comprising polybutene. The sealing material for spray coating according to any one of claims 1 to 3, wherein the temperature below the embrittlement temperature is a temperature 10 ° C or more lower than the embrittlement temperature. delete The sealant for spray application according to any one of claims 1 to 3, wherein the rubber-based sealant is pulverized at a temperature below the embrittlement temperature in a liquid nitrogen atmosphere. A rubber-based sealing material having a viscosity of 20 to 200 Pa · s / 100 ° C. is pulverized at a temperature below its embrittlement temperature to obtain a powder having a particle diameter of 3 to 8 μm, and then the powder is placed at a temperature below the embrittlement temperature. A method of applying a sealing material comprising spray coating on the surface to be coated. The method for applying a sealing material according to claim 7, wherein the rubber-based sealing material contains butyl rubber. The coating method of the sealing material of Claim 8 which further contains polybutene. The method for applying a sealing material according to any one of claims 7 to 9, wherein the temperature below the embrittlement temperature is a temperature 10 ° C or more lower than the embrittlement temperature. delete The method for applying a sealing material according to any one of claims 7 to 9, wherein the rubber-based sealing material is pulverized at a temperature below the embrittlement temperature in a liquid nitrogen atmosphere. The application method of the sealing material in any one of Claims 7-9 whose surface to be coated is an inner surface of a pneumatic tire. The coating method of the sealing material in any one of Claims 7-9 whose temperature of a to-be-coated surface is 20 degreeC or more and 60 degrees C or less.